A screen will appear with all the options you have for booking a vacation - when, how long, and who will go on vacation. Flights can be booked for immediate departure or 6 days in advance. The more advance notice you give, the bigger the discount in airfare. This matters the most if you are taking 4 or more Sims on vacation.
Vacations can last from 3 to 7 days. Just make sure you watch the hotel costs if you plan a long vacation. It adds up quickly if you need multiple rooms.
The third part of planning a trip is who will make it on the vacation list. The Sim booking the flight can invite friends and family not living in the house. You'll be prompted to hire a nanny if you leave any kids behind.
Picking a hotel is last on the list. You can decide where to stay when booking the vacation or wait until you arrive at your destination. A description and cost rating is given for each hotel available.
Once all the decisions are made, click OK, and a taxi will be dispatched to take Sims on vacation.

